• Microbiology and Biotechnology Letters
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• v.5 no.3
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• pp.127-131
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• 1977

Various kinds of native herbage grasses like-Miscanthus sinensis, Arundinella hirta, Cymbopogen geirngii, Themeda japonica etc. are widely distributed in every Korean mountain. So we investigated the availability of native grass, Miscanthus sinensis as a substrate for the production of S. C. P. The results were obtained as follows. 1) At the alkali treatment, NaOH was the most effective with the exclusion of lignin, and pretreated Miscanthus with NaOH appeared to be a good substrate for the microbial growth. 2) When Miscanthus was treated with one to 10％ NaOH, the microbial growth increased in proportion to the increased alkali concentration. Beyond 4％ NaOH, a slight increase was observed. 3) Phosphoric acid, as a neutralizer, was the most effective in cell production after alkali treatment. 4) On the effect of incubation time, the productivity was best found at 60 hours, and the cell weight was 9.23 mg per 1 ml, and the microbial digestibility of substrate was 75.2％.

• Korean Journal of Organic Agriculture
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• v.20 no.1
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• pp.81-89
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• 2012

This study was investigated to evaluate the effects of fertilizer application of surface and broadcast for rice culture on the soil chemical, physical, and microbial properties as well as growth and yield of rice. The application was made with 'Dongjin 1' rice at Jeollanam-do Agricultural Research & Extension Services from 2008 to 2010. Soil organic matter and cation concentrations were increased by surface and broadcast applications, respectively. Plots treated by surface application tended to be higher seasonal N-mineralization rate in the organic fertilizer and seasonal soil organic matter than those of broadcast application. Soil physical properties seemed to be improved by the broadcast application, and soil microbial properties were increased by the surface application. Surface application increased 5% of rice yield compared to that of broadcast.

• The Korean Journal of Mycology
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• v.16 no.3
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• pp.162-174
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• 1988

To separate and quantitate antitumor protein-bound polysaccharides of Coriolus versicolor, the constituents were obtained from the submerged culture of the mycelia(C) and from the extract of the carpophores of the wild fungus(N). The polysaccharides were degraded by methanolysis. The neutral monosaccharides were separated and quantitated by HPLC using microbondapak carbohydrate analysis column, refractive index detection and water-acetonitrile acetic acid elution. The analyses of these constituents by HPLC showed that the natural constituent(N) consisted of glucose, xylose and mannose, the average amount being 96.44, 2.16 and 1.73%, respectively. The fermentation constituent(C) consisted of mannose, glucose, xylose and galactose, the average amount being 61.30, 14.00, 12.95, and 11.75%, respectively. The analyses of these constituents by an amino acid analyzer showed that both C and N contained 17 amino acids.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.621-626
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• 2016

The present study evaluated the variations in soil microbial population of controlled horticultural land used for lettuce (Lactuca sativa) cultivation by their fatty acid methyl ester and chemical properties. We utilized four treatment groups, no treatment (NT), culture medium (CM), Bacillus subtilis S37-2 (KACC 91281P) ${\times}10^6CFU\;mL^{-1}$ (BS1), and Bacillus subtilis $S37-2{\times}10^7CFU\;mL^{-1}$ (BS2) and analyzed these variations throughout the before treatment and harvesting stage. The chemical properties such as pH, organic matter, available phosphate, and electrical conductivity in soils before treatment and harvesting stage showed no significant difference among the treatments. Total numbers of bacteria and microbial biomass C in soil treated with BS1 were larger than those of NT, CM, and BS2, whereas total number of fungi at the harvesting stage was significantly lower in the BS1 soil than in the NT and CM soils (P < 0.05). On basis of leaf length, leaf width, leaf number and leaf weight, the growth characteristics lettuce on the soil treated with BS1 and BS2 was faster than those of NT and CM soils. Yield of lettuce with treated BS1 and BS2 were 35% and 29% more than that of NT, respectively.

• Membrane Journal
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• v.12 no.1
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• pp.21-27
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• 2002

The formation of soluble microbial products(SMP) and molecular weight distribution on loading rate were observed in batch-type culture medium, which phenol was fed as a substrate. The molecular weight destribution was obtained by using 30K, 100K dalton and $0.45{\mu}$ membrane filters. When the phenol concentrationas a substrate was 120, 230 and 440 mg/L , the specific substrate utilization rate(q) showed 0.639, 1.281 and 1.744 mgTOC/mgMLSS/day, respectively. The endogenous biomass decay rate constant($K_d$) at each substrate concentration was 0.00536, 0.0661 and 0.0749($day^1$), respectively. The $SMP_e$ product rate constant($k_{SMP}_ e$) showed 0.006, 0.0058 and 0.0057($day^1$), respectively. The initial influent substrate during the course of time degraded and produced $SMP_s$. The $SMP_s$ was converted to the $SMP_{nd}$ and endogenous phase converted to the $SMP_e$ ingredients. The molecula weight distribution on loading rate was converted to a higher MW during the course of time.

• Journal of Microbiology and Biotechnology
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• v.32 no.6
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• pp.749-760
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• 2022

α-Galactosidase is a debranching enzyme widely used in the food, feed, paper, and pharmaceuticals industries and plays an important role in hemicellulose degradation. Here, T26, an aerobic bacterial strain with thermostable α-galactosidase activity, was isolated from laboratory-preserved lignocellulolytic microbial consortium TMC7, and identified as Parageobacillus thermoglucosidasius. The α-galactosidase, called T26GAL and derived from the T26 culture supernatant, exhibited a maximum enzyme activity of 0.4976 IU/ml when cultured at 60℃ and 180 rpm for 2 days. Bioinformatics analysis revealed that the α-galactosidase T26GAL belongs to the GH36 family. Subsequently, the pET-26 vector was used for the heterologous expression of the T26 α-galactosidase gene in Escherichia coli BL21 (DE3). The optimum pH for α-galactosidase T26GAL was determined to be 8.0, while the optimum temperature was 60℃. In addition, T26GAL demonstrated a remarkable thermostability with more than 93% enzyme activity, even at a high temperature of 90℃. Furthermore, Ca²⁺ and Mg²⁺ promoted the activity of T26GAL while Zn²⁺ and Cu²⁺ inhibited it. The substrate specificity studies revealed that T26GAL efficiently degraded raffinose, stachyose, and guar gum, but not locust bean gum. This study thus facilitated the discovery of an effective heat-resistant α-galactosidase with potent industrial application. Meanwhile, as part of our research on lignocellulose degradation by a microbial consortium, the present work provides an important basis for encouraging further investigation into this enzyme complex.

• Applied Chemistry for Engineering
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• v.34 no.3
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• pp.327-329
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• 2023

In this study, an experiment was conducted to investigate the effect of the concentrations of tryptone, an organic nitrogen supplement, and sodium tungstate on the growth of microbial and the production of acetic acid and ethanol in the culture of Clostridium ljungdahlii. Microbial growth increased by 144.6%, and ethanol and acetic acid production improved by 8.6% and 36.7%, respectively, when 2.5 g/L of tryptone was added to the medium of the control experiment (0 g/L tryptone). In the experiment with 1 µM Na₂WO₄·2H₂O, which is 100 times higher than the condition of the medium used in the control experiment (0.01 µM Na₂WO₄·2H₂O), there was no significant difference in microbial growth or total production of C2 metabolites, but ethanol production increased and acetic acid production decreased. As a result, the ethanol/acetic acid production ratio increased significantly from 0.24 in the control experiment to 0.56.

• Journal of the Korean Applied Science and Technology
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• v.39 no.6
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• pp.831-838
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• 2022

An auxin-producing bacteria, KSD16, KSD33, and KSD36 were isolated from agricultural soil. The strain KSD16, KSD33, and KSD36 was classified as a strain of Arthrobacter sp. based on phylogenetic analysis of 16S rRNA gene. The isolated KDS16, KDS33, and KSD36 was confirmed to produce indole-3-acetic acid (IAA), which is one of the auxin hormones. When the concentration of IAA was assessed the maximum concentration of IAA, 206.62 mg L^-1, was detected from the culture broth incubated in R2A medium containing 0.1% L-tryptophan for 48 h at 28 ℃. To study the effect of IAA producing bacteria on germination rate, seeds of Mung bean were prepared for each treatment. KSD16, KSD33, and KSD36 showed significant increase in root length and number of adventitious roots than the controls. To investigate the growth-promoting effects on the crops, Arthrobacter species were placed in water cultures and seed pots of mung beans. In consequence, the seed germination of mung beans was 73.4% higher than the control.

• Journal of Life Science
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• v.26 no.5
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• pp.571-583
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• 2016

Biogenic amines are produced primarily by microorganisms found in fermented foods and are often implicated in poisoning incidents in humans. In this study, 620 strains of microorganisms were isolated from traditional Korean fermented food in Sunchang in order to screen for non-biogenicamine-producing microorganisms present in these foods. One strain was identified and named Bacillus subtilis SCJ1, by using 16S rRNA sequencing and biochemical characterization. We investigated the cell growth of this organism in order to understand its potential for industrial application. To this end, we optimized the culture medium constituents by using the response surface methodology. The Plackett-Burman experimental design was used for screening of the medium constituents, such as molasses, yeast extract and peptone, for improving cell growth. In order to determine the optimal concentration of each constituent, we used a central composite design. Consequently, the optimized concentrations of molasses, yeast extract and peptone were predicted to be 27.5 g/l, 7.5 g/l and 17.5 g/l, respectively. By model verification, we confirmed that a 1.49-fold increase in dry cell weight compared to the basal medium-from 1.32 g/l, to 1.9722 g/l-was achieved.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.829-835
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• 2012

The cultivation of genetically modified (GM) crops has increased due to their economic and agronomic advantages. Before commercialization of GM crops, however, we must assess the potential risks of GM crops on human health and environment. The aim of this study was to investigate the possible impact of Bt rice on the soil microbial community. Microbial communities were isolated from the rhizosphere soil cultivated with Bt rice and Nakdong, parental cultivar and were subjected to be analyzed using both culture-dependent and molecular methods. The total counts of bacteria, fungi, and actinomycetes in the rhizosphere of transgenic and conventional rice were not significantly different. Denaturing gradient gel electrophoresis (DGGE) analysis of PCR-amplified 16S rRNA genes revealed that the bacterial community structures during cultural periods were very similar each other. Analysis of dominant isolates in the rhizosphere cultivated with Bt and Nakdong rice showed that the dominant isolates from the soil of Bt rice and Nakdong belonged to the Proteobacteria, Cloroflexi, Actinobacteria, Firmicutes, and Acidobacteria. These results indicate that the Bt rice has no significant impact on the soil microbial communities during cultivation period. Further study remains to be investigated whether the residue of Bt rice effect on the soil environment.